Hair-raising stem cells identifiedOctober 05, 2005Using an animal model, a research team led by Yann Barrandon at the EPFL (Ecole Polytechnique Federale de Lausanne) and the CHUV (Lausanne University Hospital) has discovered that certain cells inside the hair follicle are true multipotent stem cells, capable of developing into the many different cell types needed for hair growth and follicle replacement. In an article appearing in the Oct 3 advance online edition of the Proceedings of the National Academy of Sciences, they demonstrate that these holoclones can be used for long-term follicle renewal. In 2001, Barrandon was part of a French research team who reported in the scientific journal Cell that stem cells could be used to generate skin containing hair and sebaceous glands in mice. But at that time it was unclear whether the stem cells in hair follicles were true stem cells, capable of long-term renewal, or multipotent progenitor cells that would not permanently engraft in the follicle. In the current PNAS study, the Swiss researchers have answered that question, using rat whisker hair follicles to demonstrate that the clonogenic keratinocytes in hair follicles are true stem cells. Barrandon's group isolated stem cells from rat whisker follicles, labelled them, and grew them in culture for 140 generations. They then implanted progeny cells into the skin of newborn mice whose hair follicles were just being formed. This skin was then grafted onto athymic (nude) mice. Some cells were incorporated into developing follicles, but other follicles were completely made up of labelled cells. Each progeny cell contributed to the formation of eight different types of cell in the follicle, including those of the outer root sheath, inner root sheath, the hair shaft, the sebaceous gland and the epidermis. After 125 days, a biopsy was taken from the graft, and labelled stem cells were isolated, subcloned, cultivated and then once again transplanted. The rat whisker stem cells participated again in forming all the cell types needed to form the hair follicle and sebaceous glands, resulting in hair bulbs that underwent repeated normal phases of growth, rest and regeneration. The fact that the transplanted cells participate in the hair cycle over long periods of time shows that they are true multipotent stem cells and not progeniture cells. "With the progeny of a single stem cell, it would be theoretically possible to generate the complete hair bulb of a human being, and one that would last for years," explains Barrandon. The ability of the stem cells in hair follicles to repeatedly regenerate all the different cell types of the follicle and sebaceous glands has important implications for regenerative medicine. The method could one day be used to regenerate hair on patients with severe burns. This study is a logical complement to other work in Barrandon's Laboratory of Stem Cell Dynamics, recognized for research into the reconstruction of injured tissues and organs. Ecole Polytechnique Fédérale de Lausanne |
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| Related Stem Cells Current Events and Stem Cells News Articles First reconstitution of an epidermis from human embryonic stem cells Stem cell research is making great strides. This is yet again illustrated by a study carried out by the I-STEM* Institute (I-STEM/ Inserm UEVE U861/AFM), published in the Lancet on 21 November 2009. The I-STEM team, directed by Marc Peschanski has just succeeded in recreating a whole epidermis from human embryonic stem cells. Bone Implant Offers Hope for Skull Deformities A synthetic bone matrix offers hope for babies born with craniosynostosis, a condition that causes the plates in the skull to fuse too soon. Your Own Stem Cells Can Treat Heart Disease The largest national stem cell study for heart disease showed the first evidence that transplanting a potent form of adult stem cells into the heart muscle of subjects with severe angina results in less pain and an improved ability to walk. The transplant subjects also experienced fewer deaths than those who didn't receive stem cells. Is hepatic differentiation of embryonic stem cells induced by valproic acid and cytokines? Embryonic stem (ES) cells, known for their capacity to proliferate indefinitely and differentiate into almost all types of cells including hepatocytes, have raised the hope of cellular replacement therapy for liver failure. Paradoxical protein might prevent cancer One difficulty with fighting cancer cells is that they are similar in many respects to the body's stem cells. By focusing on the differences, researchers at Karolinska Institutet have found a new way of tackling colon cancer. The study is presented in the prestigious journal Cell. U of M researchers find 2 units of umbilical cord blood reduce risk of leukemia recurrence A new study from the Masonic Cancer Center, University of Minnesota shows that patients who have acute leukemia and are transplanted with two units of umbilical cord blood (UCB) have significantly reduced risk of the disease returning. The use of stem cells in regenerative medicine may also be detrimental for health The use of stem cells in regenerative medicine is not always beneficial for human health, it may even be harmful according to a work done by the University of Granada and University of León. Scientists have demonstrated that transplantation of human mononuclear cells isolated from umbilical cord blood exerted a deleterious effect in rats with liver cirrhosis. Penn Study Provides First Clear Idea of How Rare Bone Disease Progresses An international team of scientists, led by researchers at the University of Pennsylvania School of Medicine, is taking the first step in developing a treatment for a rare genetic disorder called fibrodysplasia ossificans progressiva (FOP), in which the body's skeletal muscles and soft connective tissue turns to bone, immobilizing patients over a lifetime with a second skeleton. Iowa State University researcher discovers key to vital DNA, protein interaction A researcher at Iowa State University has discovered how a group of proteins from plant pathogenic bacteria interact with DNA in the plant cell, opening up the possibility for what the scientist calls a "cascade of advances." Scientists successfully reprogram blood cells Researchers have transplanted genetically modified hematopoietic stem cells into mice so that their developing red blood cells produce a critical lysosomal enzyme -preventing or reducing organ and central nervous system damage from the often-fatal genetic disorder Hurler's syndrome. More Stem Cells Current Events and Stem Cells News Articles |
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